Summary of work: Nutrition evaluation in the male and female participants of the Baltimore Longitudinal Study of Aging (BLSA) has been carried out by periodic collection of 7-day dietary diaries and by measurement of vitamin levels in plasma. The dietary technique has provided data over a 36 year period in men and a 16 year period in women. The ages of the participants range from 20 to 95 years. Since the BLSA is a multi-disciplinary study, it is possible to carry out correlations between nutritional intakes and levels and other primary related variables and outcomes. We are continuing the collection of 7-day food intake diaries in collaboration with USDA and HNRCA scientists (see above). It is anticipated that the 1997-1999 time period (the T cycle) will complete data collection for the 1990's wave and will allow longitudinal analysis of dietary intakes in the 1960's, 1970's, 1980's, and 1990's - an incomparable experience. Subjects have been identified who have shown larger than average increases in their Mean Corpuscular Volumes over time. It is hypothesized that this segment of the BLSA population may include subjects with relative folate deficiencies. An analysis will be made in collaboration with scientists in the Laboratory of Personality and Cognition to examine potential correlations with early cognitive decline.